As described in FR 2 937 928, it is known to provide trim elements equipped with a skin of the aforementioned type, making it possible to display icons directly on the skin, said icons indicating certain functions or states of the vehicle. Such trim elements are in particular used to trim the dashboard of the motor vehicle, situated under the windshield of the vehicle.
The zone forming the icon is generally arranged opposite a light source intended to backlight the icon.
One critical point is the diffusion of the light transmitted by the light source through the skin. The skin must in fact have good resistance over time, and in particular good resistance to abrasion and aging, to allow satisfactory diffusion of the light throughout the lifetime of the vehicle.
Aliphatic polyurethane has satisfactory performance in terms of light diffusion and resistance to abrasion and aging. However, aliphatic polyurethane is a very expensive material, which cannot be adapted to certain lines of motor vehicles.
One aim of the invention is to provide a skin of the aforementioned type, locally adapted to diffuse the light coming from a backlight source, offering good resistance to abrasion and aging, and having a reduced cost.
To that end, the invention relates to a skin of the aforementioned type, comprising, in said region, at least one first zone in which the skin comprises an outer layer, formed by a first translucent polyurethane material, and an inner layer, covered in all locations of the skin by the outer layer, and formed by a second polyurethane material, different from the first polyurethane material, and at least one second zone, in which the skin comprises only said outer layer.
The skin according to the invention can comprise one or more of the following features, considered alone or according to all technically possible combination(s):
the first material is aliphatic polyurethane;
the second material is aromatic polyurethane.
The invention also relates to a trim element comprising a skin as defined above, and a substantially rigid substrate, the skin covering said substrate.
The trim element according to the invention may comprise one or more of the following features, considered alone or according to all technically possible combinations:
the substrate delimits at least one through opening, a light source being positioned opposite the opening, on one side of the substrate, the skin extending from the other side of the substrate, and the second zone of the skin is positioned opposite the opening;
said trim element comprises a relatively flexible layer of foam inserted between the substrate and the skin, said foam layer delimiting at least one cavity between the opening of the substrate and the second zone of the skin positioned opposite said opening.
The invention also relates to a motor vehicle comprising a trim element as defined above.
Lastly, the invention also relates to a method for manufacturing a skin as defined above, characterized in that it comprises the following steps:
providing a mold;
spraying the first material on an inner surface of the mold, through a spraying head moving at a first speed in a first region of the mold, and at a second speed in at least one second region of the mold, the second speed being slower than the first speed, so as to form the outer layer; and
applying the second material on the outer layer, with the exception of the part of the outer layer situated in the second region of the mold.
The method according to the invention may comprise one or more of the following features, considered alone or according to all technically possible combinations:
the second material is sprayed;
when the second material is sprayed, a removable protective mask is applied on the part of the outer layer situated in the second region of the mold.